The influence of the phosphorus and calcium content of feeds on growth, feed conversion and slaughter quality, and on the chemical, mechanical and histological parameters of the bone tissue of pigs.

Abstract

In a 2 X 4 factorial experiment on 96 individually housed pigs, 2 calcium/phosphorus ratios (1.3 and 1.9) and 4 phosphorus levels (0.4, 0.5, 0.6, 0.7% total P) were tested. The influence of the treatments on growth, feed conversion and slaughter quality was measured. The experiment showed the 1.3 Ca/P ratio to be more favourable than the 1.9 ratio. A P content of 0.6% was sufficient for good growth and favourable feed conversion. The quality of the bone tissue, for which the specific response resistance to distortion and breaking was used as a standard, was close to maximum when P in the feed was 0.6%. The strength of the whole bone, measured as the bending moment for distortion and breaking, was greatest when P was highest; mineralization of the bone also showed a further increase when the P content in the feed increased from 0.6 to 0.7%.During the experiment only a few cases of leg weakness were noted; these occurred throughout all the experimental treatments. On the basis of the results, the P and Ca requirements for optimal growth and feed conversion for the modern Dutch pig are 0.6% and 0.78%. More of these minerals in the feed may, however, increase deposition in the skeleton. (Abstract retrieved from CAB Abstracts by CABI’s permission)